I hope you have windows. I recommend you download Notepad++ and then make a "Find" search "Find in Files" and specific the configuration files location of privoxy. Then you search for the following :
Blacklist
or
WhiteList
Then in the file that will conclude in the above search, you can add your URL ; try whitelist www.apple.com and blacklist block www.apple.com/itunes .
The reason we do the search as above, is to find the fine that has the URL block list. A text based search inside privoxy config files should reveal the file. The file contents should look like this :
######################################################Blacklist
######################################################{ +block }
######################################################
www.apple.com/itunesWhitelist
######################################################{ -block }
www.apple.com